Steam-boiler.



No. 810,078. PATENTED JAN. 16 1906.

A. PARPITT.

STEAM BOILER.

APPLICATION FILED MAR.20,1906.

2 SHEETS-SHEET l.

QXEtwaooeo PATENTED JAN. 16, 1906.

A. PAR FITT. STEAM BOILER. APPLIO ATION FILED HAILZO, 1905.

UNITED srA'rns PATENT OFFICE.

STEAM-BOILER.

Specification of Letters Patent.

Patented Jan. 16, 1906.

A plic ti n fil d March 20, 1905. Serial No. 251,059-

To all whom it may concern:

Be it known that I, ALFRED PARFITT, a citizen of the United States, residing at Topeka, in the county of Shawnee and State of Kansas, have invented a new and useful Steam- Boiler, of which the following is a specification.

This invention relates more particularly to the connections between the fire-box crown and shell sheets of a boiler; and the principal object is to provide a novel and simple structure that will constitute an efficient connection, is not readily broken by the varying strains, is not liable to leak at the joints, and can be readily placed in position and removed without materially affecting or changing the sheets.

It is well known to those skilled in the art that with the modern boiler and higher steampressure carried the shellsheets are being made thicker and stronger and that the thicker the sheets are made the more the stay-bolts break. This is true more espe cially toward the sides of the fire-box, where the expansion of the same is vertical, which expansion causes the bolts to have a swinging hinge-like movement and effects the breakage thereof very quickly. The reason for this appears to lie in the rigidity of the sheets, which will not permit the same to bend or buckle with the rise or fall of the fireboX end of the bolt.

I am aware that a number of flexible stays have been proposed to overcome the breaking and that they do to a very considerable degree obviate the difficulty; but they are objectionable on several grounds, first, because they are expensive, in application, and, furthermore, because there is no indication when the same are broken.

Therefore another and very important object in the present invention is to retain the inflexible stay-bolts and the heavy shellsheets, but to provide means for connecting the same, which means will permit the expansion and contraction of the parts and the necessary play of the bolts with a minimum amount of injury to either.

In the accompanying drawings, Figure 1 is a sectional view through a portion of an ordinary type of boiler, showing the shell and crown sheets connected by the improved means, two devices being illustratedone in elevation, the other in section. Fig. 2 is a similar view, but showing a single slightlymodified form of connection. Fig. 3 is a sectional view through a boiler of the type having comparatively thick shell-sheets and showing the improved connections of the bolts with the same. Fig. 4 is a plan view of a portion of said sheet and Fig. 5 is a sec tional view similar to Fig. 3, but showing the modified form of connection illustrated in Fig. 2. Fig. 6 is a detail sectional view through another modification.

Similar reference-numerals designate corresponding parts in all the figures of the drawings.

In the embodiment illustrated the shell or saddle sheet is designated 3 and the fire-box crown-sheet by 4, the same being located at suitable distances apart and connected by suitable stays 5. Each of these stays consists of a shank 6, having a head 7 at its inner end that abuts against the inner face of the crown-sheet. The portion of the shank directly adjacent to the head is threaded, as shown at 8, and is adapted to receive a jam or look nut 9, screwed thereon and having a tapered end 10, that coacts with the outer face of the crown-sheet. A washer 11, of copper, maybe interposed between the sheet and nut in order to prevent leakage; but as some classes of water in connection with copper will set up galvanic action and injure the crown-sheet this copper washer may be dispensed with.

The outer portion of the shank 6 passes through the shell-sheet 3 and has threaded thereon nuts 12 and 13, located on opposite sides of said shell-sheet and having tapered or balled opposing inner portions 14, which portions are adapted to fit in recesses 15, formed in the opposite faces of the shell-sheet about the shank. If necessary, a copper washer 16 may be interposed between the outer nut or outer face of the sheet.

In applying the radial stays the outer end of the shank is passed through the crownsheet, the washer 11 and nut 10 being then placed thereupon, after which the nut 12 is threaded upon the outer portion of the shank and the outer end of said shank is thereupon passed through the shell-sheet. The inner portion of the shank is then screwed into the crown-sheet and the locknut is driven home. The nut 12 is afterward screwed out until it properly engages the shell-sheet, and the outer nut 13 is screwed tightly down upon said sheet. The device as thus set forth constitutes an efficient connection between the sheets and will withstand the varying strains without breakage. It will be a parent, moreover, from the above that the bolt can be readily placed in position. In like manner it may be readily removed, as the outer nut can be taken off, the stay broken loose at the crown-sheet, and then taken out of the shellsheet, thus doing away with the drilling, tapping, and riveting of the stay, as is ordinarily the case, and, furthermore, obviating the necessity of enlarging the openings in the sheets whenever new stays are placed therein.

A slight modification of the structure is shown in Fig. 2. The sheets are designated, respectively, 4* and 5 and the shank 6 is the same as that already described, with the exception that the outer portion is threaded farther down. The said shank 6 has a head 7 and a lock-nut 8 coacting with the crownsheet,while anut 9 coacts with the outer side of the shell-sheet 5 and has an inner tapered or balled portion 10 fitting in a recess 11*. As it sometimes happens that the boiler-head bracing is in the way and as it would be difficult to screw up the nuts 12, a sleeve 12 may be placed upon the shank 6, and the nut 13, located below the same, can be screwed upwardly, thus forcing the sleeve 12 outwardly. The outer end of the sleeve is tapered, as shown at 14 and is adapted to engage in a socket 15 in the inner side of the shell-sheet 5 about the shank.

The embodiment illustrated in Fig. 3 is particularly valuable. The shell or saddle sheet is designated 3' and is made comparatively thick for the high pressure boiler. The crown or fire-box sheet is shown at 4 Mounted on the outer side of the shell-sheet is a comparatively thin reinforcing-bolt-receiving sheet 5', suitably secured to the sheet -as, for instance, by means of rivets 6 Radial stay-bolts 7 constructed as illustrated and described in Fig. 1, are employed, these bolts having heads 8 at their inner ends and having their inner portions threaded through the sheet 4 as shown at 9. Nuts 10 having tapered ends 11 threaded on the bolts, bear against the outer side of the sheet 4*, and washers 12 may be interposed between the same and the sheet. The outer portions of the bolts 7 pass through comparatively large openings 13 formed in the thick shell-sheet 3 and said outer portions are threaded through the sheet 5'. Nuts 14*, threaded upon these portions of the bolts 7 are located in the openings 13 said openings being sufficiently large to loosely receive the same and the nuts 14 having tapered or balled portions 15 seated in sockets 16'- in the inner sides of the sheet 5*. Other nuts 17 similar to the nuts 13 described in connection with Fig. 1, are threaded upon the projecting ends of the bolts 7 b and bear against the outer side of the. sheet 5 said sheet being provided with seats or recesses to receive the same.

In Fig. 5 a slight modification of the structure is illustrated, the inner or fire-box sheet being designated 4 and the outer sheet being designated 5 On this outer sheet is placed a-supplemental sheet 6 secured thereto by rivets 7 The connection comprises a boltshank 8, having a head 9 at its inner end and a lock-nut 10 coacting with the sheet. A nut 11 coacts with the outer side of the sup plemental sheet 6 and has an inner tapered or ball portion 12 fitting in a recess 13 in the outer face of the sheet 6. A sleeve 14? is placed upon the shank and extends through an opening 15 in the shell-sheet 6 by means of a nut 16. The outer end of the sleeve is tapered, as shown at 17 and is adapted to engage in a socket 18 in the inner side of the sheet 6 about the shank.

It is to be noted that these latter structures have all the advantages of the embodiment of the invention shown in Figs. 1 and 2, and, furthermore, by employing the supplemental sheet the expansion and contraction can take place without danger of breakage to the bolts, for the supplemental sheet is made thin enough to buckle in order to permit the necessary expansion and contraction, while the inner shell-sheet can be as thick as desired. Therefore no matter how high a pressure is wanted the shell-sheet can be increased to Withstand the same, while the light sheet is employed for the direct connections. It will of course be noted that in this embodiment it is not absolutely necessary to employ the exact arrangement and construction of bolts shown, as other forms of connections can, perhaps, be employed. Thus in Fig. 6 the outer sheet is shown at 3 and the inner sheet at 4 the outer sheet having a supplemental sheet 5 secured thereover and thereto. A tie-bolt 6 suitably secured to the inner sheet, has its outer end threaded into and headed over the outer or supplemental sheet 5, as shown at 7 said bolt passing through an opening 8 in the main outer sheet 3 It is to be noted that the outer sheets 3 and 5 and 3 and 5 constitute, in effect, the sections of a shell-sheet and may be so construed.

From the foregoing it is thought that the construction, operation, and many advan tages of the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

. Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. In a boiler,the combination with a shellsheet, of a fire-box crown-sheet, a radial staybolt connecting the sheets and having a head that fits against the inner face of the crownsheet, said bolt having a shank, that portion of which that is adjacent to the head being threaded and screwed into the crown-sheet, said shank having its outer end connected to the shell-sheet, and a nut screwed upon the threaded portion of the shank and having a tapered inner end that coacts with the outer face of the crown-sheet.

2. In a boiler, the combination with spaced sheets, of a shank connected to one of the sheets and passing through the other, and clamping devices mounted on the shank and having tapered opposing faces that coact with the opposite faces of said other sheet.

3. In a boiler, the combination with spaced sheets, of a shank connected to one of the sheets and passing through the other, said other sheet having its faces recessed about the shank, and clamping devices mounted on the shank and having tapered opposing faces that fit in the said recesses.

4. In a boiler,the combination with spaced sheets, of a shank connected to one of the sheets and passing through the other, and clamping devices adjustably mounted on the shank and having rounded opposing faces that coact with the faces of said other sheet about the shank.

5. In a boiler, the combination with spaced sheets, of a shank connected to one of the sheets and having a threaded outer end passing through the other sheet, said other sheet having its faces recessed ab out the shank, and clamping-nuts screwed upon the threaded portions of the shank on opposite sides of said other sheet and having rounded faces that fit in the recessed portions of said sheet.

6. In a boiler, the combination with a shellsheet, of a fire-box crown-sheet, a radial staybolt having threaded inner and outer portions that pass through the sheets, a head on the inner end of the shank bearing against the inner face of the crown-sheet, a nut threaded on the inner portion of the shank and having a tapered end that coacts with the outer face of the crown-sheet, and nuts threaded on the outer portion of the shank on opposite sides of the shell-sheet and having their opposing faces rounded, said shell-sheet being recessed about the shank to receive the rounded faces of the nuts.

7. In a boiler, the combination with spaced sheets, one of said sheets having a portion thinner than the surrounding portions of the same sheet, of a stay-bolt connecting the spaced sheets, said bolt engaging the said thinner portion of the one sheet and being spaced from the thicker surrounding portions of the same, said thinner portion bending or buckling to permit the relative expansion and contraction of the sheets.

8. In a boiler, the combination with spaced sheets, one of said sheets comprising sections arranged flat against each other and one of said sections being thinner than the other, of a connection between the spaced sheets, said connection being engaged with the thinner section and spaced from the thicker section and said thinner section bending or buckling to permit the relative expansion and contraction of the sheets.

9. In a boiler, the combination with spaced sheets, one of said sheets comprising overlying sheet-sections located flat upon each other, of a connection between the spaced sheets, said connection being free from the inner sheet-section and engaged with the outer sheet-section.

10. In a boiler, the combination with a crown-sheet, of a comparatively thick shellsheet having openings therethrough, a supplemental sheet-section secured thereupon and extending over a plurality of the openings, a fire-box sheet, and a plurality of stay bolts engaged at their inner ends with the fire-box sheet, said staybolts passing through the openings of the shell-sheet and being engaged with the supplemental sheet.

11. In a boiler, the combination with inner and outer sheets, of a stay-bolt connecting the sheets, a sleeve fitted upon the bolt and bearing against one of the sheets, and a nut threaded upon the intermediate portion of the bolt between and in spaced relation to the sheets, said nut bearing against the inner end of the sleeve to force the outer end of the same against the sheet.

12. In a boiler, the combination with inner and outer sheets, of a stay-bolt connecting the sheets, a sleeve fitted upon the bolt and having a tapered end that bears against one of the sheets, and a nut threaded upon the bolt and bearing against the sleeve to force the I tapered end thereof against the sheet.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

ALFRED PARFITT.

Witnesses ED MINARD, OHAs. BOAST. 

